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John Curl's Blowtorch preamplifier part III
John Curl's Blowtorch preamplifier part III
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Old 22nd July 2019, 03:20 AM   #25861
john curl is offline john curl  United States
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There might have been some Bybee technology in the space program, even from the moon landing. It would have been used for improving S/N in communications, but it would have been heavily classified then. It was used in submarine warfare during the Cold War for passive sonar for sure. Of course, Bybee's latest stuff is more from German research today, regarding atomic resonance.
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Old 22nd July 2019, 03:33 AM   #25862
syn08 is offline syn08  Canada
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I wonder how come Jack is not in a maximum security federal institution for divulging and disseminating strategic technologies to foes. Does he have a licence to export Bybees to Iran, China, Russia? That is required, since even some Tektronix scopes from the 60’s are today still on the no export list.

John, to protect you last drop of reputation, tell me in private how much is your share of revenue from the Bybee business and I’ll cover it, even if I have to open a public subscription. It is painful to see you this low.
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Old 22nd July 2019, 03:52 AM   #25863
chris719 is offline chris719  United States
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John Curl's Blowtorch preamplifier part III
I'd like to believe that there is a financial motive, but there probably isn't.
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Old 22nd July 2019, 03:54 AM   #25864
anatech is offline anatech  Canada
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John Curl's Blowtorch preamplifier part III
Hi Mark,
You know what I mean in as much as this is a very relaxed forum. The last thing we need is the word or "term" police. If you want to wear that hat, be my guest, but you will be a very busy bee.

-Chris
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Old 22nd July 2019, 04:18 AM   #25865
Markw4 is online now Markw4  United States
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Quote:
Originally Posted by anatech View Post
Hi Mark,
You know what I mean in as much as this is a very relaxed forum...
Hi Chris,
If we are talking about the expectation bias thing, I think misuse of the term is a problem (more so over at the less civilized other forum out there) and we should talk about whether there is actually such a bias or not. Probably, there is not research evidence for it like we are sometimes asked to produce around here. That's okay though. There is existing research that probably helps give clues as to what might actually be going on when people make errors of listening. It's a little less pat that simply saying expectation bias however.

On the other hand, if we are talking about my interactions with a particular member, that would be a entirely different thing. A bit of a puzzle, and an unwanted one.

One thing I can tell you in any case, I don't like spending much time in this thread. A problem is that once a post is made, there always seems to be some follow up activity called for. Getting that stuff sorted and then back out of the fray again can be tricky.

Last edited by Markw4; 22nd July 2019 at 04:21 AM.
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Old 22nd July 2019, 04:50 AM   #25866
john curl is offline john curl  United States
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Old Bybee info:
Attached Images
File Type: jpg Picture 99.jpg (396.7 KB, 136 views)
File Type: jpg Picture 99a.jpg (380.7 KB, 133 views)
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Old 22nd July 2019, 05:04 AM   #25867
Terry Demol is offline Terry Demol  Australia
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Originally Posted by syn08 View Post
P.S. In case you are wondering, yes, for 99.999% of adult population, I believe all decent non pathologically designed and built amplifiers sound the same. Myself, I do not claim that my 100W/8ohm 1ppm @20KHz power amplifier sounds anywhere better than an old Harman Kardon 3770 I salvaged for $25 at the flea market.
I clearly remember some pretty specific subjective attributes being described of your PGP (<1ppm dist @ 20kHz) amp in the 'listening tests' section where it was compared to some other pretty expensive amps.

The link is now not working but I have found another reference here:
Sound Quality Vs. Measurements

I'm confused, what is your stance on this? You published the listening tests, are you saying you don't agree with the results?

From what you are saying above, they all should have sounded the same.

T
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Old 22nd July 2019, 06:15 AM   #25868
syn08 is offline syn08  Canada
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The link is working History

My stance of this: I don’t need or want to agree or disagree with anything. That was an open and causal wet listening session, I stayed slightly more sober than the average and took some notes. No claims of objectivity or test protocol, everybody knew what they are dealing with, no comparison with other amplifiers was attempted. All additional equipment was brought in by the participants. This is a story telling and it should be taken at face value, I’m myself not claiming a damn thing about any SQ.

To me, beyond a pleasant day with friends, the most important outcome was that one of the channels was slightly bursting into oscillations due to a wrong cap in the compensation loop. Fixed that, everything was fine ever since.
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Old 22nd July 2019, 06:21 AM   #25869
PMA is offline PMA  Europe
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Results in the 4ohm speakers were dissapointing. To make a long(ish) story short, the PGP is unable to properly drive 4ohm speakers up to it's full power of 200W/ch. The PGP OPS deliveres and estimated of 15A peak and that's definitely not enough to drive 4 ohm speakers (dipping at 2 ohm, plus the phase lag) at full power. However, up to about 100W/channel, the 4 ohm performance is comparable with the 8 ohm load performance. One to another, my conclusion is that lateral MOSFETs are not recommended for the ultimate performance in 4 ohm speaker loads. A good lesson for the "lesson learned" phase of this project.
Have you tried a more powerful version, later (more pairs or different output dev.)?
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Old 22nd July 2019, 06:32 AM   #25870
scottjoplin is offline scottjoplin  Wales
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Or, closer to you, a certain referendum where FUD scored a glorious victory that eventually you will all dearly pay for.
Sad, but true, and I fear we may be leading the way.........
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